Symone Sanders was deeply upset in May when the graphic video surfaced of Ahmaud Arbery being shot while jogging surfaced, and she made sure her boss, Joe Biden, saw it. Weeks later, it was Sanders who told Biden about the explosive video of a police officer kneeling on George Floyd's neck. Again? Biden asked in disbelief. Sanders responded, she recalled in an interview, Again. Again. This literally just happened again. The brutal 8-minute, 46-second video touched off a national reckoning and demonstrations across the country. And it threw Sanders, 30, into a unique, high-pressure role as the highest-profile African American staffer in Biden's inner circle, tapped to explain - or justify - his record on race to sometimes-skeptical black activists even while advising him privately on how to navigate the moment. The campaign deploys her to marquee shows like Fox News Sunday to make the case for Biden. She has been dispatched to reassure voters when Biden makes tone-deaf comments. Internally, she advises Biden on a wide-range of issues, including his response when a crisis erupts in the country's rapidly shifting racial justice landscape. But as a bridge between Biden and black activists, Sanders sometimes finds herself taking shots from all sides. Biden, after all, is trying to harness the energy from the massive street protests while rejecting the protesters' most visible demands, such as defunding the police. Some civil rights leaders grumble that Sanders hasn't done much to get Biden to meet the moment. Aimee Allison, founder of She the People, which advocates for minority women in politics, has criticized Biden for not reaching out enough to voters of color. You have millions and millions of people - some who supported other candidates in a large primary,...